Numerous types of vehicles such as railcars, semi-trailers, barges, etc., are configured to transport materials such as liquids and gases from one location to another. Such vehicles are provided with an integral or extraneous container for containment of the materials. In some cases, the materials being transported can include hazardous materials. During transit, contained materials can be influenced by environmental conditions, such as hot or cold ambient temperatures from outside the container, the monitoring of these materials, such as measuring temperature, can be useful in many applications, but is especially useful for hazardous materials that might be heat sensitive, reactive, volatile, or ones that tend to “auto-refrigerate” when leaking. In this regard, such hazardous materials can pose a significant safety risk, and therefore it would be advantageous to provide sensors for remotely monitoring conditions that can provide an indication that the materials have become volatile or are approaching volatility. Also, due to the various container constructions and the types of material being transported, interfacing such sensors with hazardous materials in a manner to provide an accurate and reliable indication of the condition of the materials while maintaining safety requirements can be extremely difficult.
In some cases, mobile containers will include a thermo-well (i.e., temperature well) to provide a point for manually checking the temperature of material in the container. A thermo-well is generally known in the art and is typically comprised of a tube or basin that extends into a container but remains sealed off from the material situated inside the mobile container. The thermo-well contains a material with a high heat-transfer rate, wherein heat energy is transferred between the material in the thermo-well and the material in the container, thereby allowing for the temperature of the material to be obtained by reference of a temperature reading from the thermo-well.
The use of a thermo-well can be particularly useful when the material inside a container is hazardous, temperature sensitive, and/or susceptible to contamination from outside the container, which can destroy the usability of the material, such as when the material is a consumable. The current configuration for many mobile containers, such as transport containers, is to include a thermo-well with a single access port. Using the single access port configuration and following the current compliance regulations, temperature monitoring via the thermo-well can only be conducted when the car is stationary and deemed to not be “in transportation.” When the container is stationary, an operator can access the singe access port and insert a temperature probe into the thermo-well to obtain temperature data. Although, placing an operator in such close proximity to the material can be dangerous when the material is a hazardous material and various conditions exist, such as when an undesirable temperature shift has occurred and/or a safety device has failed.
Another method of monitoring a mobile container is by affixing a temperature sensor to an outer surface of the mobile container. This configuration also includes several drawbacks. More particular, the temperature sensor is subject to slow sensing of temperature changes and can also provide inaccurate and unreliable information due to a plethora of factors, such as the ambient temperature outside the container, the thickness of the mobile container walls, etc., and as such, can fail to timely and reliably detect hazardous conditions. In addition, a surface mounted temperature sensor is subject to cracking or breaking away from the outer surface of the mobile container, thereby leaving a container of hazardous material without any remote means for monitoring so as to warn personal of a safety hazard prior to approaching the container.
Further, even when using a thermo-well, other significant considerations must be addressed when the thermo-well is utilized with certain materials. In particular, all openings on hazardous material tank railcars fall under securement regulations governed by the Department of Transportation. These openings, such as the thermo-well opening, must be secured while the tank car is in transportation to prevent any accidental release of a hazardous material. Any sensor fitting that interfaces with such an opening must meet the Department of Transportation requirements and be validated through approval by the Association of American Railroads.